1. Field of the Invention
The present invention relates to an ornithopter-type propulsion system for a vehicle body that generates thrust by flapping a plurality of wings. More specifically, the present invention relates to an inverting wing propulsion system for a vehicle body that drives a plurality of wings in a reciprocating motion characterized by a downward arcuate motion that generates an upward thrust and by an upward motion that generates a reduced downward thrust.
2. Description of the Related Art
Many attempts have been made to construct aircraft that fly by mimicking the flight motion of birds and insects. Such devices are usually called ornithopters. Typical prior art ornithopters attempt to propel an aircraft by actuating a wing or wings to oscillate in a series of alternating up and down strokes in order to generate thrust, much like a bird or insect will propel itself by stroking its wings.
However, such prior art omithopters have generally failed to achieve sustained flight or even lift off under their own power. One possible reason for the continuing failure of ornithopter vehicles to achieve flight could be that that the upward thrust generated by the wing or wings of the ornithopter during a downward stroke is negated by the downward thrust generated by the wing or wings during a return upward stroke. That is to say, in a typical prior art ornithopter, the flapping motion of the wing or wings does not operate to generate any net upward thrust on the aircraft, such that the aircraft is never propelled to achieve flight. Accordingly, there is a general need for an ornithopter-type device capable of driving a wing or wings in a downward motion so as to generate an upward thrust, while at the same time returning the wing or wings to a raised orientation in a manner that generates a reduced or minimized downward thrust such that a net upward thrust is generated by the motion of the wing or wings and the aircraft achieves flight.